In recent years, solar cells have been receiving attention as a clean energy source due to the rise in awareness of environmental problems. In general, a solar cell module constituting a solar cell has a configuration in which a transparent front substrate, a front surface side sealing material sheet, a solar cell element, a rear front side sealing material sheet, and a rear surface protective sheet are laminated sequentially from the photoreception surface side, and has the function of generating electricity by sunlight being incident on the solar cell element.
Solar cell elements that generate electricity inside a solar cell module are generally provided in a plurality of numbers inside the solar cell module, and are configured so as to be connected in series/parallel, to obtain the required current and voltage. In order to wire the plurality of solar cell elements inside the solar cell module, for example, a collector sheet is used for a solar cell which is formed by laminating metal foil to become a circuit on the surface of a resin sheet as a base material (see Patent Document 1).
Incidentally, the solar cell element has a photoreception surface to receive sunlight and a non-photoreception surface located on the rear side thereof, and there is known a back contact solar cell element in which an electrode is not disposed on the photoreception surface but a plurality of electrodes with different polarities are disposed on the non-photoreception surface so as to enhance the photoreception efficiency of sunlight on the photoreception surface.
There are a variety of types of back contact solar cell elements. Other than a solar cell element of a metal wrap through (MWT) type, or an emitter wrap through (EWT) type, which includes a semiconductor substrate having a plurality of through holes that penetrate between the photoreception surface and the non-photoreception surface and in which a plurality of electrodes with different polarities are provided on the non-photoreception surface, there exists a solar cell element with a structure having no through holes.
Herein, especially in the case of extracting electricity directly from the electrode of the solar cell element with a structure having through holes, there is a risk of short circuiting between the non-photoreception surface side element as a P-electrode and the wiring section corresponding to an N-electrode.
Such short circuiting can be prevented by forming an insulating layer on the circuit of the collector sheet for a solar cell. Patent Document 2 discloses a solar cell module in which an insulating layer configured of an insulating adhesive is formed on the circuit of the collector sheet for a solar cell.
On the other hand, in recent years, there are some cases where the solar cell element cracks or a contact failure occurs in a joining section of the solar cell element and the circuit on the collector sheet for a solar cell due to a slight shock from the outside, but the insulating adhesive is typically a curing resin cured by heat, UV or the like, and hence the insulating layer after curing does not have shock resistant properties, whereby it is not possible to achieve the effect of softening shocks from the outside only by means of the insulating layer.
[Patent Document 1] Japanese Unexamined Patent Application, Publication No. 2007-081237
[Patent Document 2] Japanese Unexamined Patent Application, Publication No. 2010-157553